package com.gxkj.drm.util;

/**
 * 验证码工具类
 * Created by changxiangyang on 2017/10/9.
 */

import org.apache.commons.lang3.StringUtils;

import javax.imageio.ImageIO;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.util.Random;


public class ValidateCode {


    private Random random = new Random();
    private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";// 随机产生的字符串

    private static int ONE_MINUTE = 60;
    private int width = 80;// 图片宽
    private int height = 26;// 图片高
    private int lineSize = 40;// 干扰线数量
    private int stringNum = 4;// 随机产生字符数量

    /*
    * 获得字体
    */
    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    }

    /*
    * 获得颜色
    */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /*
    * 绘制字符串
    */
    private String drowString(Graphics g, String randomString, int i) {
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
                .nextInt(121)));
        String rand = String.valueOf(getRandomString(random.nextInt(randString
                .length())));
        randomString += rand;
        g.translate(random.nextInt(3), random.nextInt(3));
        g.drawString(rand, 13 * i, 16);
        return randomString;
    }

    /*
    * 绘制干扰线
    */
    private void drowLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    /*
    * 获取随机的字符
    */
    public String getRandomString(int num) {
        return String.valueOf(randString.charAt(num));
    }


    /**
     * 生成随机图片
     */
    public void getRandcode(final HttpServletRequest request, HttpServletResponse response,String key) {

        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));
        g.setColor(getRandColor(110, 133));
        // 绘制干扰线
        for (int i = 0; i <= lineSize; i++) {
            drowLine(g);
        }
        // 绘制随机字符
        String randomString = "";
        for (int i = 1; i <= stringNum; i++) {
            randomString = drowString(g, randomString, i);
        }
        // 验证码加密
        String ciphertext = MD5.md5(randomString);
        // 将加密的验证码放入Cookie中
        final Cookie cookie = new Cookie(key, ciphertext);
        cookie.setPath("/");
        cookie.setMaxAge(ONE_MINUTE);
        response.addCookie(cookie);
        g.dispose();
        try {
            ByteArrayOutputStream tmp = new ByteArrayOutputStream();
            ImageIO.write(image, "png", tmp);
            tmp.close();
            Integer contentLength = tmp.size();
            response.setHeader("content-length", contentLength + "");
            response.getOutputStream().write(tmp.toByteArray());// 将内存中的图片通过流动形式输出到客户端
        } catch (Exception e) {
            e.printStackTrace();
        }finally{
            try {
                response.getOutputStream().flush();
                response.getOutputStream().close();
            } catch (Exception e2) {
                e2.printStackTrace();
            }
        }
    }

    public static boolean checkRandcode(final HttpServletRequest request, String cookieName, String checkValue) {
        //获取cookie里面的验证码信息
        String code = CookieUtil.getCookie(request, cookieName);
        if(StringUtils.isNotEmpty(checkValue) && StringUtils.isNotBlank(code)) {
            String ciphertext = MD5.md5(checkValue.toUpperCase());
            return code.equalsIgnoreCase(ciphertext);
        }
        return false;
    }
}